MK50240

FK50240 - Top Octave Synthesiser Chip - TOSChip

Coming soon… replacements for MK50240, MM5832, MM5833, and many many more!!

The original MK50240 was called a top octave synthesiser. However it didn’t actually synthesise anything, it just divided down a master clock using ‘approximate’ divisions to give the top octave for various keyboard instruments.

The originals are getting rare, and we keep getting asked to do something about it, so, in true FlatKeys spirit, decided to make not just a replacement (to keep those older instruments going) but a revolutionary true synthesiser with accuracy to match the expectations of the 21st Century.

Contact Chris on:
tel +44 (0)1723 352347 / mob (0)7835 252385
chris@flatkeys.co.uk

16 July 2010: THE FIRST ONE’S JUST BEEN MADE...SCROLL DOWN THE PAGE FOR PICTURES!!

50240
50242
AY-1-0212
ECG-2043
M50240
M50241
M50242
M5891A
M5891B1
MC1180L
MC1183L
MC1184L
MC86B1
MM5832
MM5833
MM5843

MO82B
MO83B
MO86B
MO87B
S2555
S2556
S50240
S50241
S50242

Specials (additional charge applies - please contact us if you need replacements for these):
147196
AY-3-0214

FK50240 is a compatible replacement for the following chips:

Our FK50240 replacement chip has 12 real synthesisers that tune from the original master clock to the desired notes, with a worst case error of
0.05 milliHertz.

[1 Hertz is one beat per second, 0.1 Hertz (100 milliHertz) is one beat in 10 seconds, 0.01 Hertz (10 milliHertz) is one beat in 100 seconds so the worst error is one beat in about 5.5 hours!! The original was 12Hertz out (worst case) which is 12 beats per second – that’s why they sound ‘off’, especially higher up.]

The FK50240 can work with any supply voltage between 8v and 16v (the originals were 11v-16v).

The FK50240 copies any vibrato (on the master clock), just like the originals – but now with the correct tuning!!

The basic FK50240 device is set to one of two scales:

a) Equal temperament – Modern tuning.

b) Original division ratios (like the MK50240)

Select your requirement on order - equal temperament or original.

The FK50240 device can have two additional control inputs:
1) The ‘Scale’ input, which is used to change the ‘scale’ type between equal temperament and original.
2) The ‘Transpose’ control input, which is used to change key, so all you Polymoog owners can now make key changes with the flick of a switch; the same applies to other instruments.
Select on order (prices above right)

What should I buy?
The price for TOSChip FK50240 includes:
- Basic TOS device - completely universal for any of the TOS made.
- Standard unit and header boards.
You will need to be able to wire up and solder the appropriate part of the device to suit your specific device to replace (instructions provided).

Extras/Services
- Scale switch
- Transpose switch
- We will create the chip-specific device ready to plug ‘n’ play for a small additional charge.

Snapping off the board

The pictures below show the ‘chip’ parts of the FK50240 - more to come soon!

Best bit at the end....with kind permission from Bradley Lehman, there will be THREE tunings available from the outset:

- equal temperament

- original division ratios

AND

- the Bach-Lehman 1722 “well-tempered”

Click this link for YouTube video of Bradley Lehman tuning a harpsichord to the new tuning.

These header pieces configure the standard connector to the original TOS.

This piece is common to all and solders into the target board

Standard connector, via ribbon cable, to the header(s)

A combination of solder blobs on these pads tells the FK50240 which original TOS it has to work with.